Bolt actuated cover for ejection ports in firearm receivers



June 14, 1960 F. P. REED 2,940,201

BOLT ACTUATED COVER FOR EJECTION PORTS IN FIREARM RECEIVERS Filed March 4. 1959 I5 Sheets-Sheet 1 g; m 9 a d w f F. P. REED June 14, 1960 BOLT ACTUATED COVER FOR EJECTION PORTS IN FIREARM RECEIVERS Filed MB-I'Ch 4. 1959 3 Sheets-Sheet 2 INVENTOR. F'ra :15 risk JP. Raed BY J M01; 9 0,1 @M

June 14, 1960 F. P. REED 2,940,201

BOLT ACTUATED COVER FOR EJECTION PORTS IN FIREARM RECEIVERS Filed March 4. 1959 3 Sheets-Sheet 3 INVENTOR. Frederick P. E a 8 l3 l9 BY p -olwaa BOLT ACTUATED COVER FOR EJECTION roars IN FIREARM RECEIVERS Frederick P. Reed, Ludlow, Mass., assignmw the United States of America as represented by the Secretary of the Army Filed Mar. 4,1959, Ser'. No. 707,316 7 s or. 42-16) V (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to firearms and more particularly to covers for closing the ejection ports in the receivers thereof.

It is an object of this invention to provide for a firearm having a port in the receiver thereof for the ejection of fired cartridge cases a cover which is actuatable between open and closed positions responsive to cyclic operation of the firearm and which is secured in the closed position during inoperation of the firearm to prevent foreign matter from entering the receiver.

It is another object of this invention to provide such a cover which is biased to the open position by spring means and is cam actuated to the closed position by the firearm bolt during cyclic reciprocation thereof.

It is still another object of this invention to provide such a cover which is easily assembled to the firearm and is simple in construction and positive in operation.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

Fig. l is a top view of a firearm receiver with the cover mounted thereto and disposed in-the closedpositron;

Fig. 2 is a partially cross-sectioned top view showing the cover in the open position and a fired cartridge case in position to be ejected through the ejection port;

Fig. 3 is a view taken along line 3-3 of Fig. 1;

i Fig. 4 is a view taken along line 44 of Fig. 2;

Fig. 5 is an enlarged view taken along line 5-5 of Fig. 2 but showing the retainer being installed in the receiver;

Fig. 6 is a view similar to Fig. 5 but showing the retainer fully installed and the cover in the closed position; 7

Fig. 7 is a reduced exploded view showing the receiver, cover and retainer in perspective; and

Fig. 8 is a reduced perspective view of the bolt showing the cam therein for actuating the cover.

Shown in the figures is a firearm provided with acylindrical receiver 12 in which a bolt 14 is actuatable from and to battery position in recoil and counterrecoil strokes responsive to forces produced by the discharge of cartridges in the firearm barrel (not shown). Bolt 14 includes a cylindrical body portion 16 with a neck portion 1% of reduced diameter extendin forwardly therefrom. Bolt 14 is spring-biased to the battery position by a pair of springs 29 so as to be returnable thereto after each cycle of operation. Mounted to the front end of neck portion 18, as best shown in Fig. 8, is a pair of extractors 17 for releasably removing a fired cartridge case 24 from the firearm barrel (not shown), and a conventionally actuated ejector 19.

Extending upwardly through receiver 12 from the inside thereof is arectangular port 22 for the ejection of tet the fired cartridge case 24 from the receiver. Port 22 is closable by a cover 26 which isof approximately the same size as such port and which is replaceably mounted to receiver 12 for actuation between an open and a closed position as hereinafter described.

Integrally fixed to the underside of one of the longitudinal edges of cover 26 is a pair of longitudinally spaced mounts 28 having longitudinally aligned bores therethrough for nonrotatably receiving, as by press fit, a rod 30. Rod 30 extends beyond the front and rear ends of cover 26 to provide end portions 34- which are received for rotation in a pair of semicylindrical recesses 36 which extend inwardly from the outside of receiver 12 adjacent the ends of one of the longitudinal sides of port 22.

The end portions 34 are replaceably secured in the recesses 36 by a retainer 38 which is substantially U- shaped in configuration and which, when assembled to receiver 12, as hereinafter described, is receivable by port 22 so as to contact the end walls of port 22 and the longitudinal wall thereof which is opposite that extending between the recesses 36.

Each of the ends of retainer 38 is bifurcated by a slot 40 having sufiicient width to rotatably receive the end portions 34 without free movement therebetween. The slots 40 form lower prongs 42 which extend beyond the end portions 34 to be pivotally receivable in undercut portions 44 extending into the longitudinal wall of port 22 which extends between the recesses 36. The slots, 40 also form upper prongs 46 which extend over the end portions 34 of rod 30 when retainer 38 is fully installed; in receiver 12.

Retainer 38 is installed to receiver 12 by positioning, the lower prongs 42 angularly into the undercut portions 44, with the end portions 34 positioned within the slots 40, and then pressing downwardly and inwardly on the longitudinal portion of the retainer until moved into port 22 and in contact with the adjacent longitudinal wall thereof. Thus, the ends of retainer 38 are secured against outward displacement from port 22 because of the engagement of the lower prongs 42 with the undercut portions 44 and, consequently, the end portions 34 are secured againstoutward displacement from the recesses 36 because of the engagement of such end portions by the upper prongs 46. The engagement of the upper prongs 46 with the end portions 34 at the same time prevents the inward displacement of the lower prongs 42 from the undercut portions 44 because of the engagement of the end portions with the recesses 36.

Retainer 38 is releasably held in the installed position through the cooperation of an elongated detent 43 protruding from the longitudinal portion of the retainer with a mating recess 50 in the adjacent longitudinal wall of portZZ. Retainer 38 is fabricated from spring stock and the longitudinal portion thereof is arranged to bow outwardly, relative to the end portions thereof, so that detent 48 is resiliently pressed into recess 50 when aligned therewith. A thumbnail clearance 52 is provided in the outer surface of receiver adjacent port '22 and detent 48 to provide means for pressing a suitable tool against the longitudinal. portion of retainer 38 to disengage the detent from recess 50 and thereby free the retainer for pivotal removal from receiver 12.

Cover 26'is spring pressed to an open position by a spring '54 which includes a pair of coils 56 which encircle rod 30 between the mounts 28. The coils 56 are integrally joined by a U-portion 58; which contacts the with the arm portions pressing thereagainst the coils 56 V 3 7 are energized to bias the coverto the open position thereof.

Cover 26 is actuatable;-to the closed position against the bias of spring 54 through the cooperation ot a lug 6 2, whichextends angularly intoireceiver .12 from the rear one of themounts 28 with a cam 64in the front 6 portion of body '16. (3am 64 is formedby a triangular ejeetion of the fired cartridge case by ejector 19 through the port when adjacent thereto.

Thus, when bolt 14 is in battery position, port 22 is closed by cover 26 through the engagement ,of lug 62 with the outside surface of body 16 When bolt 14 is actuated in the recoil stroke by the ,force'of a cartridge discharged in the firearm bar-rel '(not shown), recess 66 comes into registry with lug 62 which'has been .in sliding contact with the exterior surface ofbody 16. When recess 66 is in registry with lug 62, cover 26 is freed to be biased to the open position ,by springt54 to open port 22 for the ejection .of thefired cartridge case 24 carried by'the extractors 17 when adjacent the port.

, wardly from body16, cover 26 is opened in time for'the During the ensuing counterrecoil stroke of bolt 14, t

lug 62 is contacted by earn 64 for actuation of cover 26 to closed position and is directed by the cam to the outside'surface of body 16 for sliding contact therewith to maintain the cover in closed position until bolt 14 is reenergized for recoil travel.

From the foregoing it is clearly apparent that there is herein provided for firearms with ejectionports in the receivers'thereof a cover which is controllably actuated between a closed and an open positionby the bolt assembly and is easily assembled to the receiver and which, therefore, makes an important contribution to the art.

Although a particular embodiment of the invention has been described detail herein, it is evident that many variations may be devised within the spirit and scope for biasing said cover to a position for opening the port,

a bolt disposed in the receiver for cyclic reciprocation from a battery position to carry the fired cartridge cases to the port, a lugextending from said cover into the receiver, and a cam disposed in said bolt for engage ment with said lug to convert the axial movement of said bolt to pivotal movement of said cover against the bias of said spring means to close the port when the tion there through, a cover pivotally mounted on'the receiver for actuatably closing the port, springmeans operationally disposed between said cover and the receiver for biasin'g said cover to a'position for opening the port, a lug extendingin-tegrally from said cover into the receiver for sliding contact with the exterior surface of said bolt when .zsaid bolt fis in the battery position, said lug being angularly disposed relative to said cover where bysaid cover is actuated to close the port when said lug is in contact with the exterior surfaceof said bolt, a-recess disposed in'the exterior surface of said belt for registry with said ,lug to .free said lug so as a0 permit actuation of said cover by said spring means to open the port when'the fired cartridge cases are adj acentthere- .to, and a cam formed insaid recess for sliding contact with said lug as the bolt returns tobattery position to actuate .said cover for closing the port and to lead said 4 lug to the exterior surface of said bolt for maintaining said cover in position to close the port.

3. In a firearm receiver provided with a rectangular portfor the ejection of fired cartridge cases, a cover'having approximately the same area dimensions as the port ,for closure thereof, a pair of longitudinally spacedmounts integrally fixed to the underside of said cover adjacent one of the longitudinal edges thereof, a rod nonrotatably mounted through. said mounts for extension from the front'and rear ends of said cover to form end portions respective, thereto, semicylindrical recesses extending ine .wardly from the exterior surface of thereceiver adjacent the opposite ends of one of the longitudinal sides of the port forrotatably receiving said endportions, a retainer for replaceably retaining said end portions in said recesses, said retainer being substantially U-shaped in configuration and disposed forsimultaneous,engagement with the end walls of the port and the longitudinal wall thereoi-which is opposite that interposed between said recesses when said retainer is installed in the receiver, slotted portions disposed in theends of said retainer for rotatably receiving said end portions and to respectively" form lower prong portions which extend beyond said end portions to be pivotally received byundercut portions in the adjacent longitudinal wall of the port and upper prong portions which extend over said end portions whereby said end portions are restrained from displacement from said recesses and the lower prongs from said undercut portions, when said retainer is installed in the receiver, and detent, means disposed in the longitudinal portion of said retainer for resilient engagement with a mating recessin the adjacent wall of the port for releasably retaining said retainer in installed position.

References Cited in the 0t this patent UNITED STATES PATENTS 

